Electroplating apparatus and electroplating method

Abstract

In an electroplating apparatus, an electrolytic agent is filled into the portion between an anode and a dummy cathode which is opposite substantially face to face and parallel to the anode, and an electric current is supplied to this portion, thereby suppressing changes in properties of a black film during the period in which plating to a substrate to be processed is stopped. In particular, by applying an electric current to the anode immediately before plating to the substrate is resumed, the film formation characteristics of plating to the substrate can be maximally stabilized. This can reduce the consumption power and dissolution of the anode. This apparatus is particularly effective in copper plating in which the formation of a black film is significant.

What is claimed is:  
     
       1. An electroplating apparatus comprising: 
       a holder configured to hold a substrate to be processed, said substrate serving as a cathode and being connected to a cathode contact;  
       a dummy cathode placed in a position different from said holder;  
       an anode capable of facing, substantially face to face, both a surface to be plated of said substrate held by said holder and said dummy cathode; alternately;  
       a moving mechanism configured to move said anode between a position facing said substrate holder and a position facing said dummy cathode; and  
       a power supply connected between said cathode contact and said anode, and between said dummy cathode and said anode to supply an electric current between said anode and said dummy substrate, and between said anode and said dummy cathode via an electrolytic agent filled between said substrate and said anode, and between said dummy cathode and said anode.  
     
     
       2. The apparatus according to  claim 1 , wherein a surface of said anode which faces said substrate holder or said dummy cathode includes an impregnating body which contains said electrolytic agent. 
     
     
       3. The apparatus according to  claim 2 , further comprising a spacer which defines a space between said substrate and said impregnating body when said impregnating body faces said substrate held by said holder. 
     
     
       4. The apparatus according to  claim 3 , wherein the space is a distance by which a portion between said substrate and said impregnating body is filled with said electrolytic agent by a surface tension of said electrolytic agent. 
     
     
       5. The apparatus according to  claim 1 , further comprising a cup configured to exclusively accommodate said dummy cathode other than said substrate and holding said electrolytic agent. 
     
     
       6. The apparatus according to  claim 1 , wherein said dummy cathode and said anode are substantially flat plates, and said electroplating apparatus further comprises a mechanism configured to maintain said dummy cathode and said anode in parallel to each other. 
     
     
       7. The apparatus according to  claim 1 , wherein said anode is made of phosphorus containing copper. 
     
     
       8. An electroplating apparatus comprising: 
       a cup to be filled with an electrolytic agent;  
       an anode placed on a bottom of said cup;  
       a holder which holds a substrate to be processed and serving as a cathode in an upper portion of said cup, such that a surface to be plated of said substrate faces said anode;  
       a dummy cathode capable of moving, as needed, to be interposed between said anode and said substrate;  
       a moving mechanism configured to interpose said dummy cathode between said anode and said substrate to oppose said dummy cathode substantially face to face to said anode when plating of said substrate is stopped, and to retract said dummy cathode away from said anode when said substrate is to be plated; and  
       a power supply connected between said substrate and said anode, and between said dummy cathode and said anode.  
     
     
       9. The apparatus according to  claim 8 , wherein said substrate holder functions as said dummy cathode. 
     
     
       10. The apparatus according to  claim 8 , wherein said dummy cathode is a flexible cathode made of a material selected from the group consisting of a mesh metal and woven metal wires, and is retracted to an outside of said cup when said substrate is to be plated, and is introduced into said cup to face said anode when plating of said substrate is stopped. 
     
     
       11. The apparatus according to  claim 8 , wherein said moving mechanism comprises a mechanism configured to maintain said dummy cathode substantially in parallel to said anode. 
     
     
       12. The apparatus according to  claim 8 ,wherein said anode is made of phosphorus containing copper. 
     
     
       13. An electroplating apparatus comprising: 
       a cup to be filled with an electrolytic agent;  
       an anode placed on a bottom of said cup;  
       a metal plate holder which holds a substrate to be processed and serving as a cathode in an upper portion of said cup, such that a surface to be plated of said substrate faces said anode, said metal plate holder being disposed on said substrate back to back;  
       a holder control mechanism configured to dispose said metal plate holder, as a dummy cathode, to face said anode when plating of said substrate is stopped; and  
       a power supply connected between said substrate and said anode, and between said dummy cathode and said anode.  
     
     
       14. The apparatus according to  claim 13 , wherein said anode is made of phosphorus containing copper.